This invention concerns improvements in hot mix asphalt laydown machines, and more specifically, to an apparatus that desegregates aggregates and prevents segregation of aggregates which normally occurs during laydown operations of hot mix asphalt materials.
Laydown machines are employed to evenly spread hot mix asphalt paving materials for compaction by heavy rollers. Plant-mixed hot-laid asphalt mixtures are generally dumped on a prepared pavement subgrade. After the hot mixture is dumped onto the prepared surface, the laydown elevator, in operation, scoops the hot mix from the prepared surface into the laydown machine storage box. The hot mix then is carried upwardly by a feed belt into an ejector chute which ejects the mixture into a feedbox of the laydown machine. The mixture is further heated and then is evenly spread by the paving machine which forms a portion of the laydown machine. One difficulty encountered during laydown operations is the accomplishment of consistency and uniformity in the compacted asphalt mixture. Present methods for countering non-uniformity and inconsistency in the asphalt material include the use of laborers for leveling, raking, and spreading the mixture at certain locations by constant shoveling and raking as the laydown machine operates.
Thus the extent of uniformity and consistency in the compacted asphalt pavements is limited by the level of skill, diligence, and thoroughness of the shovelers and rakers that follow the laydown machine along its course of operation. Most raking operations cause segregated pockets of coarse aggregate which subsequently result in "pot holes". These pockets generally go undetected because the finer particles cover the segregated pockets.